The present invention relates to a dry etching method and more particularly to a low temperature dry etching method capable of controlling the sectional shape of etched article and achieving a high etching selectivity.
The low temperature etching method wherein etching is effected by maintaining the temperature of a semiconductor substrate to be etched at 0.degree. C. or below (which is far lower than used conventionally), is described in, for example, Japanese Patent Application Kokai (Laid-Open) No. 158627/1985.
The above prior art describes that side etching can be made very small by etching silicon at low temperatures. However, it makes no mention as to the improvement of etching selectivity or the control of sectional shape of etched article. Therefore, effecting etching by simply reducing the temperature of a semiconductor substrate to be etched has heretofore made it difficult to carry out the patterning of a multilayered film at a high precision to form fine holes having a sectional shape suitable for filling.